Nowadays, consumable electronic products with touch pads or touch panels are becoming increasingly popular because of their ease and versatility of operation. A representative electronic product with a touch panel is for example an iPhone, which is a mobile phone designed and marketed by Apple Inc. For helping the user well operate the electronic products, the touch sensing interfaces of the electronic products are developed in views of humanization and user-friendliness.
Conventionally, by simply touching the surface of the touch sensing interface with a finger, the user can make selections and move a cursor. Nowadays, with increasing demand of using the touch sensing interface as a control unit, operating the touch pads or touch panels with only one finger is not satisfied. As a consequence, touch sensing interfaces operated with two fingers have been developed. Take the iPhone for example. It is possible to zoom in and out of web pages or photos by placing two fingers on the touch sensing interface and spreading them farther apart or closer together, as if stretching or squeezing the image. The iPhone interface, however, enables the user to move the content up/down or leftward/rightward or rotate the content by a touch-drag motion of a single finger.
Although the iPhone interface makes it easy to zoom in or out of images by spreading two fingers farther apart or closer together, there are still some drawbacks. For example, since the software for reading out the user's gestures is based on complicated moving control means, there is a need of providing a simplified method for quickly reading out the user's gestures. In the present invention, capacitive or resistive touch pads are concerned.
Moreover, since the software object is moved up/down or leftward/rightward or rotated by moving a single finger on the touch sensing interface, it is necessary to rotate the software object at a specified angle or move the software object along multi-directions with two fingers. Therefore, there is also a need of rotating the software object at a specified angle or moving the software object along multi-directions with two fingers.
U.S. Pat. No. 7,138,983 discloses a method and an apparatus for detecting and interpreting path of designated positions. The U.S. patent determines whether an object should be rotated in clockwise or anticlockwise directions based on the measured angle difference value. If the measured angle difference value is negative as shown by the example on FIGS. 63A to 63D of that U.S. patent, the user's gesture is interpreted as a clockwise rotation operation. If the measured angle difference value is positive as shown by the example on FIGS. 65A to 65D, the user's gesture is interpreted as an anticlockwise rotation operation.
However, merely relying on the measured angle difference, the foregoing method may misinterpret some gestures. With reference to FIG. 13, if the user has no intention to perform a clockwise rotation operation but unintentionally contacts the touch panel at position C, the appearance of the touch point C will be interpret as the clockwise rotation operation because the measured angle difference is a negative value, i.e. (∠C-∠B)<0.